alpha-linux-user: Properly handle the non-rt sigprocmask syscall.

Name the syscall properly for QEMU, kernel source notwithstanding.
Fix syntax errors in the code thus enabled within do_syscall.
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NRichard Henderson <rth@twiddle.net>

linux-user/alpha/syscall_nr.h

@@ -46,7 +46,7 @@
 #define TARGET_NR_open		 45
 #define TARGET_NR_osf_old_sigaction	 46	/* not implemented */
 #define TARGET_NR_getxgid		 47
-#define TARGET_NR_osf_sigprocmask	 48
+#define TARGET_NR_sigprocmask    48
 #define TARGET_NR_osf_getlogin	 49	/* not implemented */
 #define TARGET_NR_osf_setlogin	 50	/* not implemented */
 #define TARGET_NR_acct		 51

linux-user/syscall.c

@@ -5881,11 +5881,10 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
             target_to_host_old_sigset(&set, &mask);
 
             ret = get_errno(sigprocmask(how, &set, &oldset));
-
             if (!is_error(ret)) {
                 host_to_target_old_sigset(&mask, &oldset);
                 ret = mask;
-                ((CPUAlphaState *)cpu_env)->[IR_V0] = 0; /* force no error */
+                ((CPUAlphaState *)cpu_env)->ir[IR_V0] = 0; /* force no error */
             }
 #else
             sigset_t set, oldset, *set_ptr;